Add accept-filter param which controls if we attempt kernel
filteringer.

Apply filters after listen() when we do.

Report failuers with VSL(SLT_Error)

Disable filters in pipe-lining test-case.

Fixes	#1101

Submitted by:	DocWilco

the original requester.

Submitted by:	DocWilco

- mention vmod_std(7)
- HEADER is released and used by vmod_std(7) so put it in its own line.
  The explanation is still needed though.
- for consistency replace leading tabs with spaces
- *fallback* are not strings so avoid mentioning the type
- use ascii characters in vmod_std(7)

And a few style changes from me to vmod_std.rst

Requested by: Federico G. Schwindt <fgsch@lodoss.net>

Reduce stacksize to 32k.

Fix previous change to not madly leak memory.

activity.

Consequent Constification

with allocating its own objcores.

When WRW is used to send stuff to the backend 'req->t_resp' is not
an appropriate base for the timeouts.